Growth mechanism in the crystallization of YBa2Cu3O6+delta from peritecticmelts

Large c-axis oriented single grain YBa2Cu3O6+delta (123) measuring up to 50 mm diameter and 40 mm in thickness have been grown by directional solidifi cation of the peritectic melts using a single crystal SmBa2Cu3O6+delta plat e as a seed in a vertical furnace. A correlative study of optical and SEM o bservations shows that the crystal growth proceeds by the growth of steps p arallel to the seed, primarily via a nucleation and diffusion controlled gr owth mechanism. Details of the growth, morphology and superconducting prope rties of the grown grain have been investigated using a variety of techniqu es, including magnetic levitation, and the results reflect the superconduct ing single grain nature of the crystallized 123 material (pellet).